Sophia Culpo Says Olivia Culpo’s Baby Is Christian McCaffrey’s ‘Twin’ (Exclusive)

Sophia Culpo was seeing double while looking at her Instagram feed.

While chatting exclusively with PEOPLE on the red carpet at the House of Champion New York Fashion Week event on Thursday, Sept. 11, the model, influencer and nutritionist recalled how a photo of her sister Olivia’s husband, Christian McCaffrey, popped up on her Instagram timeline — and she thought it was the couple’s baby daughter, Colette.

“I just sent a picture in my family group chat because Christian came on my timeline and she’s his twin, so I was like, ‘What? What are you doing on my Instagram feed?’ ” Sophia, 28, recalls. “Because I literally thought it was her. They’re like twins.”

“They’re clones,” she adds of her niece and the San Francisco 49ers running back, 29.

As for Olivia’s take on the uncanny resemblance between her husband and daughter, Sophia jokes, “Well, she did carry her for nine months, but we’re thinking it might change. We don’t know.”

Sophia says her sister, 33, and Colette are both “doing great,” and she’s a completely smitten aunt.

“I miss her so much. I haven’t seen her in a week, and she’s changing every day,” she says about the baby.

The Culpo Sisters star previously told PEOPLE in July that she was “just so obsessed” with Colette, who was born that month. “She’s just a great baby and she’s so sweet,” Sophia said at the time while attending the Create & Cultivate Festival in Los Angeles.

“It’s the best! Best,” she added of being an aunt. “Newborn bubble is just like, oh my God, I just wish I could smell her right now.”

Olivia and McCaffrey announced Colette’s birth via a joint Instagram post on July 13, sharing a series of black-and-white photos from the hospital. One image showed Olivia holding a swaddled Colette while lying in bed, as her husband leaned over with his forehead touching hers as they both looked at their tiny daughter.

In a follow-up post on Instagram Stories, Olivia described Colette’s delivery as “the scariest and most rewarding of all experiences,” and added of McCaffrey, “As soon as he came into the room, I felt most at peace.”

In yet another post, the new mom wrote, “Colette is so lucky to have the best daddy in the world. A love like no other.”

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This week, the former Miss Universe gave PEOPLE a peek into her daughter’s “serene” nursery, which she designed in collaboration with Crate & Kids. She also told PEOPLE how she and McCaffrey were being intentional about trying to “slow down and be present” with their baby.

Reflecting on her motherhood experience so far, Olivia added, “Just even seeing the world through her eyes is so rewarding.”